The 12-week advertising blitz, called "Tips From Former Smokers," is an effort to counteract the estimated $10.5 billion a year spent by tobacco companies to market and promote cigarettes in the United States.

"This is really a David versus Goliath fight. The tobacco industry has spent more than $100 billion on marketing and promotion. They continue to spend more than $10 billion a year. That's a million dollars every hour," Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, said in a telephone interview.

Some 8 million Americans have smoking-related illnesses, and as many as 443,000 Americans die each year from smoking-related causes. And while U.S. health officials have succeeded in getting many smokers to quit, recent evidence suggests the message is not getting through to America's youth.

According to the U.S. surgeon general's report on youth smoking released last week, one in four high school seniors is a regular cigarette smoker, and because few high school smokers are able to quit, some 80 percent will continue to smoke as adults.

CDC says its ads - a combination of paid advertising and public service announcements - are intended to encourage smokers to quit and to build awareness for the damage caused by smoking and exposure to second-hand smoke.

"Basically these are ads about the real effects of smoking on real people. They show cancer, heart attacks, stroke, amputation and what it's like to live with those conditions," Frieden said.

One print ad, for example, depicts Brandon, a 31-year-old double amputee from North Dakota who was diagnosed at age 18 with Buerger's disease, a rare blood-vessel disorder that cut off blood flow to both his legs. Brandon's tip: Allow extra time in the morning to put on your legs.

One of the TV spots depicts an emaciated, 51-year-old former smoker from North Carolina named Terrie getting ready for work by putting in her teeth, then putting on her wig and artfully arranging a scarf around her tracheostomy tube.

The tagline of the ad is: Smoking causes immediate damage to the body. You can quit.

Frieden said frank stories about the real health effects of smoking have been proven to discourage new smokers and to get people to quit.

"This is absolutely what works. The science is very clear," Frieden said.

A 2008 report by the National Cancer Institute found that anti-smoking media campaigns reduce smoking among both youth and adults, especially those with strong messages that play on the emotions. And a 2012 review of published studies found that testimonials warning about the risks of smoking are especially effective at getting people to quit.

Frieden estimates that about 50,000 smokers will quit as a result of these ads. "It could be higher, but that's our conservative estimate."

The advertising campaign will run on a wide range of media, including TV, radio, print, billboards, bus shelters, movies and online via Facebook, Twitter and YouTube.

The push follows big tobacco's success in federal court at blocking regulations that would have required companies to put pictures on their labels of rotting teeth, diseased lungs and other images illustrating the long-term health consequences of smoking.

But Frieden said the advertising effort was planned long before that decision was handed down earlier this month.

Dr. Len Lichtenfeld of the American Cancer Society said the ads are a good step, but they need to be part of a coordinated anti-smoking effort that includes talking about clean indoor air, tobacco taxes and smoking cessation programs.

"We have hit a barrier of smoking in this country where about 20 percent of adults are regular smokers," Lichtenfeld said in a telephone interview.

"In the past number of years, we haven't been able to reduce that number. If this campaign sends a message to people that this is a habit that has risks that can cause harm, that's a good thing," he said.